Seoul Sky

Lotte World Tower, a slender tapering spire of glass that rises 555 meters over Jamsil in southeast Seoul, is the tallest building in Korea and one of the tallest in the world. Its design draws on the gentle curve of Korean ceramics and the brush of calligraphy, and it holds offices, a luxury hotel, residences and, at the very top, Seoul Sky, the observatory that occupies floors 117 to 123. The visit begins underground with a short film and a ride in the Sky Shuttle, one of the fastest double-deck elevators in the world, whose walls light up with projections as you climb roughly half a kilometer in about a minute. You step out into a column of glass with the entire metropolitan area spread below: the Olympic Park and Lotte World's castle directly beneath, the river curling west past the bridges toward downtown, Namsan and its tower looking small in the middle distance, Bukhansan's granite peaks on the northern horizon and, on very clear days, the hills toward Incheon. On floor 118 the Sky Deck has a glass floor where you can stand and look straight down at the traffic of Jamsil, a few steps that make most visitors laugh nervously. Higher floors hold a cafe, a lounge bar for a drink with the view, and a souvenir shop, and the descent passes through gallery spaces. For the truly brave, the Sky Bridge Tour, booked separately, clips you to a harness and walks you across a steel bridge between the tower's two peaks at around 541 meters, outside. Opening hours run from late morning until late evening, with an extra hour on Fridays, Saturdays and the eve of public holidays.

Seoul Sky or N Seoul Tower? The two are complementary rather than rivals. N Seoul Tower sits on a mountain in the middle of the old city, so its view is the classic one: palaces, downtown and the river all around you, and the walk up Namsan is part of the pleasure. Seoul Sky is almost twice as high and feels genuinely vertiginous, but it stands on the eastern side of the city, so downtown and the palaces are a distant blur. Choose Seoul Sky if you want the big thrill, the glass floor and a modern, efficient visit that pairs with Lotte World and the mall; choose Namsan for atmosphere and the central panorama. Resellers sell a bundle covering both.

Timing matters as much as at any observatory. Tickets are sold for timed entry, and the slots around sunset are the busiest, especially at weekends; booking ahead online avoids the ticket queue in the basement of the Lotte World Mall. Weekday mornings and the last hours before closing are calmest. Haze is common in Seoul, particularly in spring, so check the air-quality forecast before you go — the view on a crisp autumn or winter day can stretch for tens of kilometers. Allow about an hour to ninety minutes at the top. Prices are moderate by global observatory standards, with reductions for children and combination tickets with the Lotte World Aquarium, which sits in the mall below.

Jamsil makes a full day out. The Lotte World Mall at the tower's base holds hundreds of shops, a large food court, a cinema and the aquarium; Lotte World, the indoor-outdoor theme park, is connected underground; and Seokchon Lake, ringed by cherry trees that bloom spectacularly in early April, is a pleasant walk around. In the evening, the tower is lit in changing colors, and on special occasions — New Year above all — it is the stage for some of the most spectacular fireworks in the country. Jamsil Station on Lines 2 and 8 connects directly to the complex.